GM Volt electric
vehicle
(06/10/2008)

It has an electric motor and a
conventional engine, and it can’t be classified as a zero-emissions
vehicle – but whatever you do, don’t call the GM Volt a hybrid!

“It’s an electric vehicle,” states Johan Willens, GM’s global director
of advanced propulsion and environmental communications. “The electric
motor drives the wheels at all times.” It has a 16KwH Lithium Ion
battery pack that gives the Volt a range of around 40 miles – sufficient
for most everyday use.

But what’s different is the Volt’s small petrol engine, which isn’t
coupled to the drivetrain but acts as a generator, recharging the
battery when it’s out of juice. So Volt owners won’t be stranded if they
travel for more than 40 miles.

“We call it a range extender,” says Willens. In fact, GM calls the
concept E-REV – extended-range electric vehicle – and it’ll play a major
role in GM’s environmental plans in the future.

The Volt was shown at Paris in production-ready form – and it has
changed a lot since the original Volt concept was unveiled at the 2007
Detroit Show. It’s a much more rounded shape now, and Willens says the
changes are necessary in order to optimise the Volt’s aerodynamic
efficiency – which helps add precious miles to the range.

Volt will go on sale in the US at the end of 2010, but Europe is likely
to receive other models using the E-REV concept – possibly a version of
the next-generation Zafira, which will use the same platform as the
Volt, but whose MPV body is more likely to appeal to European tastes
than the Volt’s four-door saloon.

“The system can drop in to other cars in the GM range,” says Willens.
What’s more, the petrol ‘generator’ could be replaced by fuel cells in
the future, when the technology becomes available at the right price.

What has enabled GM to produce an E-REV is the advance in battery with
Lithium Ion technology. Indeed, Willens says the concept is not a new
one: “We were working on a similar four-door car under the EV-1 project
in the 1990s, but it wasn’t possible because of the battery technology.

He says most users won’t travel for more than 40 miles a day – which
could mean the generator is rarely used. This has created other issues,
such as oil pooling in the generator, though Willens says GM has come up
with solutions for this.